The Zero-Velocity Correction Method for Pipe Jacking Automatic Guidance System Based on Fiber Optic Gyroscope.

Area of Science:

• Geotechnical Engineering
• Navigation Systems
• Signal Processing

Background:

• Pipe jacking guidance systems using fiber optic gyroscopes (FOG) offer high safety and autonomy.
• Inertial navigation systems (INS) suffer from cumulative errors over time.
• Accurate zero-velocity update (ZUPU) is crucial for error compensation but challenging in slow pipe jacking operations.

Purpose of the Study:

• To develop a robust zero-velocity detection algorithm for FOG-INS in pipe jacking.
• To address the challenge of distinguishing between moving and stationary states during slow operations.
• To improve the positioning accuracy and reliability of pipe jacking guidance systems.

Main Methods:

• Established a Kalman filter model incorporating zero-velocity update (ZUPT).
• Designed a three-conditional zero-velocity detection (TCZVD) algorithm combining moving variance of acceleration (MV), angular rate energy (ARE), and stance hypothesis optimal estimation (SHOE).
• Conducted laboratory and on-site experiments to validate the algorithm's performance.

Main Results:

• The TCZVD algorithm achieved a zero-velocity detection accuracy of 99.18%.
• Positioning error was reduced to less than 2% of the total distance.
• On-site experiments confirmed the algorithm's applicability in practical pipe jacking environments.

Conclusions:

• The proposed TCZVD algorithm effectively suppresses accumulated errors in FOG-INS.
• The method significantly improves the positioning accuracy of pipe jacking operations.
• This provides a robust solution for pipe jacking automatic guidance technology.